Question

A person does 13 J of work moving a couch 4.1 m. How much force was used?

Answer 1

Work done (`W`) by a force `F` causing a displacement of `s` is given as `W=Fs cos theta` (where, `theta` is the angle between the force and the displacement)

Now,considering that the displacement occurred alon the direction of the force applied, we get, `theta =0`, so `cos theta =1`

So, `W =Fs`

or, `F= W/s =13/4.1 =3.170 N`